Among others, it complains to me about the artists Justine, Greed, Alex Party, Winx* - ALL of which have either exact matches in the DB or easily searchable matches. The interface basically forces me to add duplicate artists; not displaying any of the trivial matches.

Why is AME not finding obviously matching entities? Aside from MBS-2467 and MBS-2564 that is...

If you click through to actually enter the edit (with all the add artists) it gives you an ISE; I'm guessing this is probably because it's violating dupe artists constraints with no comment, but test is currently broken so I can't see the full error.